Fix bounds computation of all 0-input filters.

src/effects/SkBitmapSource.cpp

Index: src/effects/SkBitmapSource.cpp
diff --git a/src/effects/SkBitmapSource.cpp b/src/effects/SkBitmapSource.cpp
index aee4a361f2050b2bf96d612fa8151c50cf2bf3c1..0d9315b2abfe77d7415afe10dd147a5e4bd8604f 100644
--- a/src/effects/SkBitmapSource.cpp
+++ b/src/effects/SkBitmapSource.cpp
@@ -97,9 +97,3 @@ bool SkBitmapSource::onFilterImage(Proxy* proxy, const SkBitmap&, const Context&
 void SkBitmapSource::computeFastBounds(const SkRect&, SkRect* dst) const {
     *dst = fDstRect;
 }
-
-bool SkBitmapSource::onFilterBounds(const SkIRect& src, const SkMatrix& ctm,
-                                    SkIRect* dst) const {
-    *dst = src;
-    return true;
-}